1. Field of the Invention
The present invention relates to an apparatus for controlling a power window regulator for opening and closing a window with a motor.
2. Description of the Related Art
In a control apparatus for a power window regulator to be used for a vehicle, the power is usually supplied through relays to a motor for vertically moving a window glass. In this case, such a relay is controlled by a semiconductor switching element which is turned ON and OFF by an operation switch operated externally. Since such a semiconductor switching element can easily be controlled to switch ON and OFF, it is used for drive control of the relays. The operation of resetting the power supply connected to a motor can also be executed by such a semiconductor switching element.
In the conventional control apparatus for a power window regulator, a semiconductor switching element and a relay coil of a relay are connected in series to the power source and, therefore, the power supply voltage is supplied to the series circuit of the semiconductor switching element and relay coil even when an operation is in the OFF state. However, in such a condition, if a noise is applied to the power supply line or the signal line for ON-OFF control of the semiconductor switching element, the semiconductor switching element typically malfunctions resulting in malfunction of the motor. This problem has lowered the reliability of control of such power window regulators.